Casting machine



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Filed June 20, 1932 5 Sheets-Sheet 4 flay 0. 206141-71: yfiyww m xwSept- R. o. WATKINS CASTING MACHINE Filed June 20, 1952 5 Sheets-Sheet 5Patented Sept. 18,1934

PTENT OFFICE (CASTING MACNE Ray 0. Watkins, Chicago, 111., assignor toUniversal Battery Company, Chicago, 111., a corporation of llllinois Myinvention relates in general to casting machines and more in particularto a casting machine for producing storage battery grids.

The principal object of the invention is the provision of an improvedcasting mechanism.

Another object is the provision of an improved mechanism for castinggrids in which the lead alloy is pumped from a lead kettle into molds insynchronism with the driving means for the mold.

Another object is the provision of improved pouring mechanism adapted tooperate in combination with a mold carrying frame.

Another object is the provision of an improved pouring mechanismincluding improved means for controlling the amount of metal poured andthe flow thereof.

Another object is the provision of an improved lead pump mechanism.

Other objects and features of the invention will ing detaileddescription taken with the accompanying drawings, wherein Fig. 1 is aplan view of the entire mechanism, the usual lead pot being partlybroken away to conserve space;

' Fig. 2 is a side elevational view thereof, part of the mechanism beingshown in section;

Fig. 3 is an elevational view partly in section looking at right anglesto Fig. 2;

Fig. 4 is an elevational view partly in section looking at the oppositeside of Fig. 2;

Fig. 5 is a plan sectional view taken along the line 5-5 of Fig. 2;

15 Fig. 6 is a sectional view taken along the line 66 of Fig. 3;

Fig. '7 is an enlarged fragmentary vertical view taken on the line '7'7of Fig. 1:

Fig. 8 is a transverse section taken through the lead pump on the line8-8 of Fig. '7;

Fig. 9 is a slightly irregular sectional view taken on the line 9--9 ofFig. 8.

Referring now to the drawings, the mold supporting and operatingmechanism includes a main base frame 11 which carries a stationaryvertical shaft 12 to which a head 13 is secured against'rotation. A moldcarrying frame 14 is rotatably supported on the shaft 12 and has securedthereto a 'mold frame extension 16 which actually carries the molds. Aframe 14 is shaped on its under side with a plurality of edge radialslots 01' grooves 17 into which one of three rollers 18 carriedv on athree arm spider 19 is adapted to engage and intermittently rotate theentire frame.

be apparent from a consideration of the follow- I For driving the threearm spider I provide a motor 21, the drive shaft of which has a smallsprocket gear 22 which drives a sprocket chain 23, the sprocket chain inturn driving arelatively larger sprocket gear 24 carried on a shaft 26.of) This shaft has a worm 2'7 which meshes with a worm gear 28 carriedon a shaft 29, which shaft 29 is suitably journaled in the main baseframe. The three-arm spider 19 is keyed to an upright shaft 31 andbeveled gears 32 and 33 carried reso spectfully by the shafts 31 and 29transmit the movementof the shaft 29 to the shaft 31.

The shaft 31, therefore, rotates continuously and the three-arm spideralso rotates continuously. The arms and slots 1'7 are so dimensionedthat a roller 18 enters a slot just as another roller 18 leaves a slot.At this time the portion of the slot which the rollers engage issubstantially tangent to the circle described by the rollers 18 so thatas a result the frame 14 is held stationary for a short length of time.When the frame 14 moves, it accelerates until the parts are in theposition shown in Fig. 5, at which place the frame is moving at its mostrapid rate. As the three-arm spider, however, continues to move in thedirection indicated by the arrow, movement of the frame 14 is graduallydecelerated until just as the arm is about to move the roller out of aslot, movement of the frame 14 is entirely arrested. By designing thedrive so that 35 one arm is engaging as the other arm is disengaging, Ifind that it is possible to obtain substantially any desirable controlof the mold carrying frame. I may even cause the frame to move slightlybackwardly as the roller 18 leaves the slot. Modifications of themovement obtained by the structure shown, however, will usually requirethat the slots 1'7 be so shaped as to be no longer truly coincident withthe radius of the frame.

The molds carried by the mold carrying frame are bi-part, one. part 34;being stationary and the other 'part 36 being relatively movable. Themolds, six in number, are carried radially of the frame and there beingsix slots 1'7 and the threearm spider 19 being proportional accordingly,each movement of the frame will be equivalent to the circumferentialspace between centers of the molds. In this Way, the molds seriatim willbe presented to the mold pouring position A (Fig. 1) at which place themolds having previously been emptied are filled with lead alloy.

A cam 3'7 on the underside of the head 13 controls the movement of themovable mold portion. A plurality of rollers 38 confined in the l cam 37are moved by the cam and are provided with connections, as shown, to themovable mold whereby movement of the rollers is imparted to the movablemolds. As Fig. 1 shows, the molds are opened at a mold dumping or griddischarging position B.

Molten lead alloy in suitable amounts is maintained in a lead pot 39 andI employ lead pumping mechanism for Withdrawing the lead from the potand discharging the same in the form of a sheet into the mold during thebrief interval at which the mold carrying frame is stationary and theempty mold is presented to the lead pouring position.

Now, as to the details of the lead pumping mechanism, I provide a leadcylinder 41 (Fig. 7) closed at the bottom by a plate 42 and having apiston 43 reciprocable therein. This entire assembly is buried under theliquid lead so that litharge, oxides, dirt or foreign matter which mayfioat on the top of the lead under no circumstances will be permitted toenter the lead pump. 1

A piston rod 440, is pivotally supported on the inside of the piston andis reciprocable in a manner to be described to operate the piston up anddown whereby, by means of the valve mechanism employed, lead iswithdrawn from the lead pot and fed to the mold.

The piston 43 is hollow and lead is delivered to the cylinder by passingthrough valve control ports 44 in the base of the piston. A valve 46 hasits stem extending through the piston face and the stem has a rim 47 forholding the valve in position. When the piston is drawn up, it isob'vious'that the lead will pass through the ports 44, forcing the valveaway fromits seat. The valve, however, being made of steel, is lighterthan the lead and tends to float to the top of the lead in the cylinderand close the ports. When the piston is moved downwardly, the valvealready being substantially against its seat is forced still tighteragainst its seat and closes the ports 44. I

The lead delivered from the lead pump passes upwardly through a pipe 47ainto a delivery nozzle 48. This delivery nozzle comprises a lowerportion 49 and an upper portion 51 secured together by machine screws52. The lower portion is provided with an extension 53 for securing thespout to a bracket 54, which bracket is attached to the side of the leadkettle by cap screws 56 (Fig. 1). The lower portion also has a boss 57into which the pipe 47a is threaded, whereby lead delivered through thepipe 47a is passed to the interior of the spout.

The lead delivery spout is fan shaped, as shown in Fig. 1, and thedelivery opening is substan' tially as wide as the gate of the gridmold. At the delivery end the vertical distance between the two portionsof the spout is relatively small. A small but sharp projection 58 runsentirely across the delivery opening.

As the lead is delivered from the pump to the delivery opening in thespout, the entire spout and the pipe 47a are maintained filled withlead. To prevent this lead from running back and also to insure arefilling of the cylinder on the upstroke of the piston, I provide aball check valve 59 (Fig. 9). This ball check valve is in a relativelyrestricted chamber, the upper portion being formed to provide a seat 61.Above the seat a radial chamber 62 is provided communicating with theinterior of the cylinder below the piston. A chamber 63 communicateswith the chamber housing the ball. The ball 59 is steel and beinglighter than the lead, it also tends to float against the seat 61. Thebody of lead in the pipe 47a and above it tends to maintain this ballagainst the seat. The pumping or downstroke of the piston, however, willforce the ball away from its seat sufiiciently to pass the lead into thechamber 63 and thence through the delivery pipe 47a.

Any suitable means for supporting the pump in the body of lead may beemployed. In the present embodiment, the cylinder 41 has sideprojections to which rods are attached, these rods being carried inprojections 65 from the bracket or frame 54. In this way the lead pumponce being set is always maintained in the same position in the leadpot. This construction, moreover, supports the lead pump firmly andfacilitates the operation of the piston and piston rod.

I operate the piston so that it moves downwardly and delivers a flatsheet of lead to the mold at the instant that the mold comes to astationary position. The lead pump, therefore, is driven in synchronismwith the mold moving and operating mechanism.

For operating the lead pump, I provide a cam 66 on the shaft 29. Thiscam engages a roller 67 carried on an arm 68, which arm 68 is keyed to atransverse shaft 69. The end of the shaft 69 projecting through the base11 has keyed thereto an arm '71. The movement of the arm 68 by the cam66, therefore, through the shaft 69, operates the arm 71; and themovement of the arm 71 is transmitted to the piston.

A rod 72 is pivoted to the arm 71 at 73. A bracket 74 carried by theframe has a fork shaped projection 76 through which the rod extends, anda spring '77 has one end bearing against the projection 76 and the otherend bearing against a nut 78 adjustable on a threaded sleeve 79 pinnedto the rod. At the upper part of the rod, a sleeve 81, loose on the rod,has one side bearing against a collar 82 pinned to the rod and the otherside against a spring 83, the opposite end of the spring being retainedby a nut 84.

The sleeve 81 carries a pin 86 which extends through a boss 87 on an arm88 pinned on a rocker shaft 89. This rocker shaft carries a second arm91 provided with a boss through which a pin 92 projects, this pin beinga projection from a sleeve 93 adjustable on the piston rod 44a.

With the construction described, the piston is raised when the arm 68 isdepressed by the cam 66 and at the same time the spring '77 iscompressed. When the cam rotates until a lower portion is adjacent theroller 6'7, the spring 77 is allowed to expand, thus forcing the pistondown on a pumping stroke and causing the roller to follow the cam. Thespring 83assists in smoothing out the action and is also of value shouldthe lead become cold and freeze in the pump. In this case, the rod 72would continue to move up and down, but the only action would be toalternately compress and expand the springs '77 and 83. It should beremembered that the spring '77 is considerably stronger than the spring83.

As shown, particularly in Fig. 2, the cam 66 is a three part cam,onerotation of the cam causing the pump operating rod to move through threecycles of operation. Since the cam is operated at the same speed as theshaft 31. carrying the three-arm driving spider, the movement of thepump and the movement of the molds is always in synchronism. Moreover,the cam is forcing the arm 68 downwardly at the same time that the moldsare being rotated; and at the stationary position of the molds, thespring 7'7 is moving the rod to cause the lead to be pumped. The speedat which the rod '72 is returned is determined by the tension of thespring 77 and accordingly this spring can be adjusted to regulate thespeed of the pumping action.

I may also' regulate the length of stroke by controlling the rockingmovement of the shaft 69. This may, of course, be accomplished bysubstituting the cam 66-for a cam of different contour. I control themovement of the shaft, however, so that the same efiect is obtained asif the cam were changed.

The shaft 69 has a control arm 96 keyed to it and this control armprojects underneath a vertically movable threaded rod 97 (carried by thebase 11). By rotating this arm, its bottom end which is engaged by thearm is adjusted. If this rod is rotated until it moves at an extremeupper portion, the roller 6'7 will be permitted to follow the cam allthe way in to the lowest portion thereof as the cam rotates. By loweringthe rod 97, however, the arm 96 which moves upwardly with the arm 68will have its upward movement arrested by engaging the rod 97. This willprevent the roller 6'7 from following the cam which will havesubstantially the same effect as if the shape of the cam were changed.Since the movement of the piston rod 4.4 is directly proportional to themovement of the operating rod 72, and the operating rod '72 in turndepends upon the rocking movement of the shaft 69, it follows thatlimiting the movement of the arm 68 keyed to the shaft 69 will limit thestroke of the pump piston.

I also provide this arm 96 for preventing the movement of the lead pumpentirely if necessary; A shut off arm 98 is pivoted to the frame at 99and has its lower end rounded and adapted to engage a roller 101 on thearm 96 cam fashion. so that movement of the arm in a counter-clockwisedirection (Fig. 4) will move the arm 96 downwardly and take the roller6'7 entirely out of contact With the cam 66.

A shut-off arm 102 for the entire mechanism is provided at a placeconvenient to the operator. This arm rotates a shut-off rod 103 whichthrough suitable mechanism disengages a main clutch 104. This clutch ison the shaft 26, which is driven directly from the sprocket chain 23.Since the movement of all of the parts is from the shaft 26, disengagingthe clutch 104 will shut off the entire mechanism. This is a temporaryshut off, however, as when the mechanism is entirely shut down, currentto the motor is shut off by means of a suitable electric switch.

The mechanism operates substantially automatically, a single workmanbeing sufiicient to care for the grids as they are discharged from themolds, to replenish the lead kettle periodically and to generallysupervise the entire operation. At each time that the mold carryingframe stops, a mold is presented to the pouring position and the pump isoperated. The shape of the spout is of importance in connection with thepouring. A wide fiat sheet is delivered to the mold each time the pistonmoves downwardly. The sharp projection 58 at the mouth of the spoutserves a useful purpose. The

' surface characteristics of the lead .are such that when the movementof lead through the spout is ceased, the lead will bead up along thesharp projection and be held there by its own surface tensioncharacteristics and its own weight, so as to seal the opening andprevent the entrance of air which would cause an oxidation of the lead.The only portion. of the lead, therefore, which is exposed to the air isa very small portion immediately at the mouth of the spout.

Lead kettles vary in shape and since it sometimes becomes necessary toemploy my mechanism with different types of lead kettles, there aretimes when the pump has to be set at an extreme angle. It is, of course,understood that I contemplate the slight changes necessary in the checkvalve so that the ball 59 will seat properly with the pump at any angle.

What I claim as new and desire to protect by' Letters Patent of theUnited States is:

1. In a casting mechanism of the character described, a lead pumpadapted for mounting in a lead pot including a stationary cylinder and apiston movable therein, a source of fiuid lead in said pot, a rotatablecam having a cam periphery with high and low points thereon, an armengaging the periphery of the cam, a rocking shaft for carrying saidarm, connections between said arm and the piston of the lead pump forreciprocating the piston, and stop means operating on said rocking shaftfor preventing the arm from following the periphery of the cam into thelowermost points thereof whereby the stroke of the piston may becontrolled.

2. In a battery grid casting apparatus, a lead pump adapted for mountingin a lead pot, said pump including a cylinder removably supported insaid pot and a reciprocable piston, a piston rod, a bell crank levermechanism, one arm of the bell crank lever mechanism connected to saidpiston rod, a cam having a peripheral cam surface with high and lowpoints thereon, a bell crank mechanismxadjacent thecam and having onearm engaging the surface of the cam, an actuating rod connected to onearm of the bell crank mechanism associated with the piston and to onearm of the bell crank mechanism associated with the cam whereby toreciprocate the piston in accordance with the peripheral shape of thecam.

3. A casting mechanism as defined in claim 2, including a spring, abracket engaging one end .of the spring and adjustable means carried onthe actuating rod engaging the opposite end of the spring, whereby saidrod is moved in one direction by the spring and in the oppositedirection by the cam, and whereby the compression in said spring may becontrolled by said adjustable means to determine the rate of returnmovement.

4. A casting mechanism as defined in claim 2, including a rocking shaftfor the bell crank mechanism adjacent the cam, a second arm secured tosaid rocking shaft, and a stop acting on said second arm to limit themovement of the actuating rod.

5. A casting mechanism as defined in claim 2 wherein the engagementbetween the rod and first mentioned bell crank mechanism includes 'asleeve carried by an arm of said bell crank mechanism, the rodprojecting through the sleeve, a collar on the rod engaging the sleeveat one end ill thereof, a spring engaging the opposite end of directionwhen spring is released, the first mentioned spring co-operating withthe second mentioned spring to permit movement of the actuating rod uponthe freezing of the piston in the cylinder:

-6. Ina battery grid casting mechanism, a lead pump including a cylinderadapted to be supported in a lead pot, a piston recipro'cable in saidcylinder, an intake valve mechanism in the base of the piston to supplythe cylinder withleaol upon movement of the piston, a discharge port insaid cylinder having a check valve therein, and a spout havingconnecting means extending from said discharge port, with said spoutbeing relatively fan shaped with a restricted opening at the deliveryend thereof, and means in said spout co-operating with the check valveand intake valve to maintain said spout filled with lead to the openingin the delivery end thereof.

7. The combination defined in claim 6, wherein said spout comprises alower and an upper portion, and a relatively sharp upwardly extendingprojection from the lower portion adjacent the outer extremity thereofrunning the full width of the mouth of the spout to facilitate controlof the lead at said spout.

8. In a casting mechanism of the character described, a lead pumpconsisting of a stationary cylinder and a piston movable therein, thepump being disposed in a body of molten lead, a rotary cam, a rod, meansfor moving said piston in response to end movement of said rod, a springsurrounding said rod, a stationary stop engaging one end of the spring,a. stop adjustably carried by the rod engaging the opposite end of thespring, and connections between the cam and rod to move the rod againstthe tension of the spring, said piston moving means operating towithdraw the piston when the rod is moved loy the cam, whereby said rodis returned by the spring on the working stroke of the piston, the speedof return being regulated by the adjustable stop on said rod.

9. In a casting mechanism of the character described, a cylinder adaptedto be inserted in a lead pot containing a supply of molten lead, meansfor holding said cylinder at an angle in said lead pot, a cylinder headclosing the lower end of the cylinder, a cup-shaped piston reciprocablein the cylinder, 9. piston rod pivotally secured to the pistonintermediate the ends thereof, a valve port in the base of the piston, avalve slidable in the base of the piston adapted to cover said port onthe pressure stroke of the piston but to allow lead to flow through theport into the cylinder on the suction stroke of the piston, a dischargenozzle, 2. connection to the discharge nozzle at the lowermost edge ofthe cylinder, and a check valvein said cylinder discharge connection.

10. In a casting mechanism of the character described, a cylinderadapted to be inserted in a lead pot containing a supply of molten lead,means for holding said cylinder at an angle in said lead pot, a cylinderhead closing the lower end of the cylinder, a cup-shaped pistonreciprocable in the cylinder, a piston rod pivotally secured to thepiston intermediate the ends thereof, a valve port in the base of thepiston, a valve slidable in the base of the piston adapted to cover saidport on the pressure stroke of the piston but to allow lead to flowthrough the port into the cylinder on the suction stroke of the piston,a discharge nozzle. a connection to the discharge nozzle at thelowermost edge of the cylinder, and a check valve in saidcylinder-discharge connection, said nozzle being fan shaped and having awidth substantially equal to a mold into which it is adapted todischarge, but restricted vertically, with a continuous sharp projectionat its lower edge.

11. In a casting mechanism of the character described, a source ofmolten lead, a discharge nozzle, pump means for withdrawing lead fromsaid source and delivering the same to the nozzle, said nozzle being fanshaped and inclined to the horizontal, the delivery mouth relativelywide but narrowed vertically, and having a continuous sharp upwardprojection at its lower edge, whereby lead is discharged in a fiatsheet, and after discharge a lead seal is formed at said delivery mouthand only a small area of lead is in contact with air.

RAY O. WATKINS.

